JPH10296555A - Automatic screw fastening machine and automatic screw fastening method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic screw fastening machine capable of correctly supplying a screw and fastening a screw on a work provided with a pilot pin. SOLUTION: This automatic screw fastening machine is constituted by furnishing a driver bit 8 free to rotate by receiving driving of a rotating drive source, a first reciprocal drive source to move this driver bit 8 in the axial direction, a second reciprocal drive source 10 free to reciprocally move integrally with the driver bit 8 and a chuck click 16 having a holding hole free to reciprocally move by specified quantity by receiving actuation of this second recoprocal drive source 10 and free to hold a screw and energized to constantly arrange this holding hole on a moving passage of the driver bit 8, and it is devised so that the chuck click 16 is moved by driving of the second reciprocal drive source 10 and the driver bit 8 is made to approach the held screw.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screw tightening machine and an automatic screw tightening method suitable for tightening a screw on a work provided with a pilot pin for guiding the screw to a fastening position.

[0002]

2. Description of the Related Art Conventionally, various types of automatic screw tightening machines have been used for fastening screws to a work. This type of automatic screw tightener has a driver bit configured to be rotatable in response to the driving of a rotary driving source such as a motor and to be capable of reciprocating in the axial direction by driving a reciprocating driving source such as a cylinder. A chuck unit is provided on the moving path of the bit so as to move integrally with the driver bit and to stop at a predetermined position by contacting a stopper or the like. The chuck unit is provided with a chuck claw capable of holding a screw on a movement path of the driver bit, and the chuck claw is configured to be supplied with a screw from a screw supply device.

[0003]

However, in the above-mentioned conventional automatic screw tightening machine, for example, when a pilot pin biased so as to protrude from the screw hole of the work toward the automatic screw tightening machine is provided, the pilot pin is not used. The chuck jaws move into the chuck jaws until they come into contact with the screws, then guide the screws to the screw holes in the work by guiding the screws with the pilot pins by moving the driver bits, and then tighten the screw by rotating the driver bits. However, in actuality, as the pilot pin enters the chuck jaws, the screws are pushed back into the chuck jaws and fall down, making it impossible to supply and fasten the screws to the work correctly. Has occurred.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an automatic screw tightening machine and an automatic screw tightening method capable of correctly supplying and fastening screws to a work provided with a pilot pin. The purpose is to: In order to achieve this object, the present invention provides a driver bit having a tip end engageable with a screw fastened to a workpiece and rotatable by being driven by a rotary drive source, and moving the driver bit in an axial direction. A first reciprocating drive source, a second reciprocating drive source that can reciprocate integrally with the driver bit, and a holding hole that can reciprocate a predetermined amount and hold a screw in response to the operation of the second reciprocating drive source. And a chuck claw that is urged to always dispose the holding hole on the movement path of the driver bit.
It is preferable that the second reciprocating drive source operates so as to move the chuck jaw to a position where the tip of the driver bit is close to the screw held by the chuck jaw.

The present invention also relates to a chuck claw arranged to hold a screw on a moving path of a driver bit which is rotatable by being driven by a rotary driving source and is reciprocally movable by being driven by a first reciprocating driving source. The screw is supplied and held, and then the chuck jaws are moved by the operation of the second reciprocating drive source until the tip of the driver bit approaches the screw held by the chuck jaws, and then the driver is operated by the operation of the first reciprocating drive source. The screw is tightened by moving the bit to push out the screw from the chuck jaws, and rotating the driver bit by driving the rotary drive source to tighten the screw to the work.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4, reference numeral 1 denotes an automatic screw tightener, and an upper guide 2 provided on a front surface of a base 2.
a and a guide shaft 3 slidably guided by the lower guide 2b.
Are slidably inserted. The driver table 4 is connected to the guide shaft 3 by a tension spring 5 so as to be constantly pulled upward, and a rotary drive source 6 is disposed at a front portion thereof. The rotary drive source 6 is a motor, and its output shaft is connected to a driver bit 8 via a transmission mechanism 7. A first part such as a cylinder connected to the driver base 4 is provided on the base 2.
A reciprocating drive source 9 is provided.
The driver table 4 is reciprocated by the operation of, and the driver bit 8 is reciprocated in the axial direction.

At the lower end of the guide shaft 3, a support base 11 on which a second reciprocating drive source 10 is disposed is fixed integrally. The second reciprocating drive source 1 disposed on the support base 11
Reference numeral 0 denotes an air cylinder, and a chuck base 12 is connected to a tip of the rod 10a which can move forward and backward. A stopper 13 is attached to the chuck base 12 so as to protrude toward the support base 11 by a predetermined amount, and a chuck unit 14 is connected below the driver bit 8.

[0008] The chuck unit 14 is a chuck body 1 configured to be able to always guide the driver bit 8.
A pair of chuck claws 16 are rotatably connected to the tip of the chuck body 15. The chuck pawl 16 is biased by a spring (not shown) so as to be always closed, and is configured to close the movement path of the driver bit 8. A holding hole 16a is formed on the opposing surface of the chuck claw 16 along the movement path of the driver bit 8, and the holding hole 16a is attached to the chuck body 15 so as to be tilted and rotatable. The screw guide tube 17 is configured to be always in communication. A hose connector 18 is fixed to the chuck body 15 so as to be in communication with the screw guide tube 17. The hose connector 18 has a feeding hose extending from a screw supply device (not shown). (Not shown) are connected.

In the automatic screw tightening machine 1, the screw sent from the screw supply device (not shown) by air pressure is
It is supplied from a feeding hose (not shown) to a holding hole 16a of the chuck pawl 16 through a hose connector 18 and a screw guide tube 17, where it is fitted and held. In response to the operation of the second reciprocating drive source 10 from this state, the chuck table 12 moves to the driver bit 8 side, that is, the direction approaching the support table 11, and
As a result, the tip of the driver bit 8 approaches the screw held by the chuck pawl 16. At this time, the stopper 13 comes into contact with the support base 11 and the lifting of the chuck base 12 stops. On the other hand, prior to screw tightening, a pilot pin 20 is disposed on the work and protrudes toward the automatic screw tightening machine 1 through a screw hole in which the screw is tightened. The pilot pin 20 is constantly urged by a spring 21 so as to be extended, and is configured to be able to retreat to the screw hole side when pressed from the tip end projecting through the screw hole.

As described above, after the chuck claw 16 is moved to a position where the driver bit 8 and the screw are close to each other, the driver table 4 is lowered by receiving the operation of the first reciprocating drive source 9.
Under the force of the tension spring 5, the guide shaft 3 is also lowered integrally,
As a result, the support base 11 and the chuck base 12 are also lowered integrally. When the chuck table 12 reaches a position where the above-described pilot pin 20 is introduced into the holding hole 16a of the chuck claw 16, the chuck table 12 comes into contact with a stopper (not shown) and stops.
At this time, as the pilot pin 20 enters the holding hole 16a, the screw is pushed up to the driver bit 8 side, but immediately comes into contact with the adjacent driver bit 8. For this reason, pushing back of the screw by the pilot pin 20 can be suppressed, and the screw can be prevented from falling in the holding hole 16a. Therefore, the screw is screwdriver bit 8
And the pilot pin 20 is held in a correct position.
And is accurately guided to the screw hole of the work.
Then, the driver bit 8 receives the drive of the rotation drive source 6 and
Is correctly screwed into the screw hole of the work as it rotates.

[0011]

As described above, according to the automatic screw tightening machine and the automatic screw tightening method of the present invention, when a screw is supplied to the chuck jaw, the chuck jaw is actuated by the second reciprocating drive source and the chuck jaw is driven. Side, and the pilot pin enters the chuck claw holding hole in the screw tightening work to guide the screw to the screw hole of the work by the pilot pin in order to move the driver bit close to the screw held in the holding hole. However, the screw to be pushed back can be supported by the driver bit, so that the screw is not pushed back and falls down in the holding hole,
There is an advantage that the screw can be supported between the pilot pin and the driver bit in the correct posture and accurately guided to the screw hole position of the work and fastened. In addition, the chuck jaws can be freely reciprocated with respect to the driver bit by the operation of the second reciprocating drive source. There is an advantage that the screwing operation can be performed by positioning.

[Brief description of the drawings]

FIG. 1 is an enlarged partial cutaway sectional view of a main part of an automatic screwing machine according to the present invention.

FIG. 2 is a front view of the automatic screw tightening machine according to the present invention.

FIG. 3 is an operation explanatory view of the automatic screw tightening machine according to the present invention.

FIG. 4 is an operation explanatory view of the automatic screw tightening machine according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic screw-fastening machine 3 Guide shaft 4 Driver stand 6 Rotation drive source 8 Driver bit 9 1st reciprocation drive source 10 2nd reciprocation drive source 11 Support stand 12 Chuck stand 14 Chuck unit 16 Chuck claw 16a Holding hole

Claims (3)

[Claims] 1. A driver bit having a tip end engageable with a screw fastened to a work and rotatable by driving of a rotary drive source, and a first reciprocating drive source for moving the driver bit in an axial direction. A second reciprocating drive source that can reciprocate integrally with the driver bit, and a holding hole capable of reciprocating a predetermined amount and holding a screw when actuated by the second reciprocating drive source; And a chuck claw biased so as to always be disposed on the path of movement of the driver bit. 2. The automatic screw according to claim 1, wherein the second reciprocating drive source operates to move the chuck jaw to a position where the tip of the driver bit is close to the screw held by the chuck jaw. Fastening machine. 3. A screw is supplied to and held by a chuck claw arranged to hold a screw on a movement path of a driver bit which is rotatable under the driving of a rotary driving source and which can reciprocate under the driving of a first reciprocating driving source. Then, the chuck pawl is moved by the operation of the second reciprocating drive source until the tip of the driver bit approaches the screw held by the chuck pawl, and then the driver bit is moved by the operation of the first reciprocating drive source. An automatic screw tightening method characterized in that a screw is pushed out from a chuck jaw and a driver bit is rotated by driving a rotary drive source to tighten the screw to a work.